Hierarchically Organized Structure of Electrospun Nanofibers from Computationally Designed Peptide Bundlemers

Synthetic peptides are excellent candidates for the design of nanoscale materials through controlled, targeted assembly with atomistic precision due to an ability to mimic complex protein structures and properties in nature. The ability to precisely design and control structure at the molecular level plays essential roles in constructing new materials with target desired structures and properties. Herein, computationally designed peptides are used to construct a hierarchically organized fiber material with exceptional mechanical properties. The basic peptide building blocks are self-assembled into coiled-coil bundles, or ‘bundlemers’, that subsequently undergo covalent conjugation between bundlemers to form polymers. The resultant hybrid peptide-based polymers formed by concurrent physical (non-covalent) and covalent interactions of bundlemers exhibit rigid-rod structure owing to a rigidity of constituent bundlemers and direct, covalent linkages between them. The resultant rod-like polymers are subsequently employed to fabricate a higher-ordered fiber material via electrospinning, while preserving their unique rod-like characteristic. Moreover, the apparent mechanical properties of the final rod nanofibers are compared with other protein-based fiber materials.